Gear pump



W. ERNST Dec. y28, 193,7.

`GEAR PUMP Filed Jan.

Z 7 mw 3 C 14a Z6 K 3ov ATTORNEYS Patented Dec. 28,1937

UNITED'STATES v i criminale` y Y waiter amt, Mount cilena, omo, um. by

mesma` nments. .to The Hydraulic Presa Corporation, Inc., Wilmington, Del., a coi'lui-` u ratione! Deia" Applicationlv January s, 1935, ser-iai maar 1My yinvention relates to gear pumps. f

, ,Itlis the object of my invention to provide a ``gear pump which will maintain the gears centered betweenthe wearplates with extreme ac- Bi curacy to prevent thescrapiiigon` the plates or` I j scraping on the housing` and possible seizing. 1

`It is a further objectto provide such an accurate `aligr'nnent of thegears thatthe `extrerney ly close clearance of .0005" can be maintained `l `in order to produce a leak-proof pump,` capable of exerting very high pressures.

dimension is approximate, but the pump adjust-` This clearance ment must be maintained closely in theneighborhoodof this clearance.

l n It is a particular feature of this pump to proffvide the use of adjustable, tapered roller bearings, and a method o1' adjusting the bearings and l of adjusting the -gears in position relative to the l `wear plates.

` `2"()` "It isalso an object to provide means to keep "the gear tightly centered Aori the shaft so there is no chance for the pressure to squeeze the fluid between the clearance plate and gears, or force `the gear against the opposite plate, which is the ting up the bearings so tight as to eliminate .radial play so that the gear cannot move in either a radial or axial direction, and cannot ride on either the -plates or the housing. Referring to theA drawing:

Figure 1 is a vertical section through the pump `on the line I-I, looking in the direction of the arrows, of Figure 2.` Figure 2 is a section on the line 2--2 of Figlure 1, lookingin the direction of the arrows.l

` `4o Referring to the drawing in detail, the numerals I and 2 designate the outersections of the pump housing. `The housing is completed by the wear plates 3 'and I. 'I'hese several members are held together by a plurality of bolts 5. 'Ihe wear plates l and 4 are so arranged as to be `spaced from the gears 6 and 'l .thatthe' clearance will be in the neighborhood of .0005".

. Gear 6 is mounted upon and turns with the driving shaft `8. This driving rshaft is mounted on a pair of oppositely 'disposedtapered 'roller bearings. The I right-hand bearing is provided with an inner race 9, mounted on the shaft 8 between the shoulder I0 and the gear face il. It

"is provided with Vtapered rollers I2 and an'outer race I2 which is clamped between the rollers I2,

the inner face` of the casingghalf 2, as at Il, and the end of the 'adjusting nut IB.

The "adJustingnut I0 isthreaded within the f casing half 2 and can v'be adjusted around thel shaft fromthe `outsideby the insertion of a 5 tool in the recesses I6.` Itis prevented from turning when onceuadju'sted by the set screw I1, mountedin the casing half 2. Y It is also providedi with a packing I8 to 'seal its engagement with the shaft 8. 1 I l The other end of the shaft 811s provided with a threaded end I9 carrying a nut 2li, which retains the inner race 2l between it and the adjacent side face of the gear 8. Rollers 22 are mounted on the inner race of this tapered roller 15 bearing. Mounted upon this series of rollers 22 is an outer race 23 which engages the inside wall 2l of that part of the casing designated I.' This outer race is also engagedA by the threaded adjusting nut 24a., which is retained ,in posi- 20 `tion by the set screw 2,5,in the casing half I. h'I'his adjusting nut has recesses 26 for the reception of an adjusting tool.

It is provided` with a leakage drain 2l. The shaft 8 is provided with a bent disposed `passageway 28 from one 25 side of the gear to the other.

The casing halves I and 2 have interiorly disposed ribs 28 and 30, which engage with the inner portions of the wear plates 3,' which are oppositely disposed on either side of the gears 6 30 and 1, where those gears mesh. Here again the clearance is maintainedas indicated. These internally extending portions `29 and 30 are provided with a passageway 3i. 'I 'he gear 1 is mounted on the stub s haft 32, which is mounted 35 in the same manner as the shaft 8. 4The only difference is that the shaft 32 does not extend outside of the casing. A

The pump is provided with an inlet or suction port n and an outlet or discharge port 34. The 40 numeral 35 designates the inlet chamber and 36 the outlet chamber.

Operation Utically disposed through the years,v and the other ends of which meet in the axial line of the shaft supported by the bearings. This plane through 5o the gears is marked AA, and theaxial line of the' shaft is markedBB, and the radial axial lines of the roller bearings are marked C. 'Ihus a very accurately balanced constructionvis provided. 55

'Ihe nut 2l holds the entire bearing assembly in position on the shaft. while the adjusting co1- lars I and 24a make possible the simultaneous adiustment of the diametral clearances of the tapered roller bearings 22 and the lateral positions of the shaft, bearings and gear relatively to the wear plates 3. By this means the clearance between the wear plates I and the gear 8 can be maintained with extreme accuracy in the neighborhood of .0005", which produces a leakproof pump capable of exerting high pressures.

It will be understood that I desire to comprehend within my invention such modifications as come within the scope of my claims and my invention.

It will be understood that when the term wear plate" is referred to in the speciilcation and claim, I am referring to any part of the casing which is adjacent to the gears. 'I'hese wear plates are in i'act a misnomer in that they are not engaged by the gears and are therefore not subject to wear, but this is the conventional term for that portion of the casing which is adjacent to the gears and as to which a predetermined close spacing must be maintained. 'The wear plates may be separate from the casing or a part of it. It will therefore be understood that while I have used the language customary in this art, it is done so with the understanding of its.

meaning in this art. The expression housing plate" instead of wear plate" is a more accurate designation, but not one customarily employed in this art.

Having thus fully described my invention. what I claim as new and desire to secure by Letters Patent, is:

In combination in a gear pump, a pair of spaced shafts, pumping gears mounted on said shafts, at least one of said shafts having an annular shoulder located inwardly of the end of the shaft and a threaded portion upon said end with a nut engaging said thread, tapered roller bearings mounted on said shaft on opposite sides of said gear, the inner races of said bearings being arranged between said gear and shoulder and nut, respectively, and in abutment therewith, said bearings,and their inner races together with the gear being assembled or disassembled as an entirety from the said end of the shaftbeyond said shoulder and all of said parts being clamped to the shaft by said nut when it is in engagement with the threaded end of the shaft, a casing for said pump adapted to slidably support the outer races of said bearings, and adjustable collars in. said casing adapted to engage said bearings for adjustably moving the bearings and the shaft with its gear` axially of said shaft to simultaneously adjust the intervals between said gear and saidA casing and also to reduce the diametral clearances of said tapered roller bearings.

WALTER ERNST. 

